On 18 March, 2011 I had a meeting with Dr.Vijay Kohli, Assistant Entymologist of Epidemic Cell with his office located at the second floor at the Kankaria Urban Health Centre in Ahmedabad.
Dr. Vijay Kohli | Assistant Entymology Health Malaria | Urban Health Centre
After speaking to Dr. Vijay Kohli, all I can say is I have immense respect for him for the magnanimous task of keeping vector borne diseases like Malaria, Dengue, Lymphatic Filariasis and others under epidemic control. His work in the field of vector borne diseases is really amazing and his constant contribution to the field of research and accumulation of data is tremendous.
He was greatly helpful to share important information, factual data and statistics with me regarding Dengue and Malaria which gave me the insight why the Dengue disease needs to be dealt with more importance at the present times than Malaria or other vector borne diseases.
He also informed me about the NVBDCP Board (National Vector Borne Disease Control Programme) whose central office is in Delhi and who are doing a lot of work in the field of vector borne diseases.
The Directorate of National Vector Borne Diseases Control Programme is the national level Technical Nodal office equipped with Technical Experts in the field of Public Health, Entomology, Toxicology and parasitology aspects of malaria. The Directorate is responsible for framing technical guidelines & policies as to guide the states for implementation of Programme strategies. It is also responsible for budgeting and planning the logistics pertaining to central sector. Monitoring of implementation through regular reports and returns of MIS is done. The Directorate carries out evaluation of Programme implementation from time to time. The resource gap is also assessed as to provide an equitable support based on the magnitude of the problem.
More information can be found here about the NVDCP: http://nvbdcp.gov.in/
Following is the interview with Dr. Vijay Kohli and the available data that he shared with me. The data and statistics are under copyright of NVBDCP and Urban Health Centre in Ahmedabad and focuses on the state of Gujarat.
1. When does Dengue occur mostly in Ahmedabad?
Dengue occurs mostly between August to November with the peak month in October in Ahmedabad.
Dengue Seasonality 2003-2010
2. How does Dengue infection affect the human body?
Dengue is usually transmitted by the mosquito Aedes Aegypti, and rarely Aedes Albopictus. The virus exists in four different types, and an infection with one type usually gives lifelong immunity to that type, but only short-term immunity to the others.
Dengue virus is primarily transmitted by Aedes mosquitoes, particularly A. aegypti. These mosquitoes usually live between the latitudes of 35 degrees North and 35 degrees South below an elevation of 1,000 metres (3,300 ft). They bite primarily during the day. Other mosquito species—A. albopictus, A. polynesiensis and several A. scutellaris—may also transmit the disease. Humans are the primary host of the virus, but it may also circulate in nonhuman primates. An infection may be acquired via a single bite. A mosquito that takes a blood meal from a person infected with dengue fever becomes itself infected with the virus in the cells lining its gut. About 8–10 days later, the virus spreads to other tissues including the mosquito’s salivary glands and is subsequently released into its saliva. The virus seems to have no detrimental effect on the mosquito, which remains infected for life. Aedes aegypti prefers to lay its eggs in artificial water containers and tends to live in close proximity to humans, and prefers to feed off people rather than other vertebrates.
Aedes Aegypti biting human
Dengue virus virions
4. Which gender is most affected by the Dengue disease ?
There is no distinction in dengue prevalence in both the sex in all age groups.
Dengue Sex-wise prevalence | 2003-2010 | Ahmedabad
3. Is there a specific human age in which dengue is more prevalent.
In all age groups dengue has been noted, however with the increase in age there is an increase in rate of Dengue. This is due to to the movement patterns of adults who travel to work. Though the number of death cases are mostly noted. Among children and pregnant ladies, the number of fatal / death cases are very high but working males are at higher risk because of their high movement rate.
Dengue Prevalence Age and Sex-wise
4. What are the symptoms of Dengue?
People infected with dengue virus are commonly asymptomatic or only have mild symptoms such as an uncomplicated fever.Others have more severe illness, and in a small proportion it is life-threatening. The incubation period (time between exposure and onset of symptoms) ranges from 3–14 days, but most often it is 4–7 days. This means that travellers returning from endemic areas are unlikely to have dengue if fever or other symptoms start more than 14 days after arriving home. Children often experience symptoms similar to those of the common cold and gastroenteritis (vomiting and diarrhea), but are more susceptible to the severe complications.
Symptoms of Dengue
5. Is there any cure for the Dengue disease?
There is currently no available vaccine, but measures to reduce the habitat and the number of mosquitoes, and limiting exposure to bites, are used to decrease the incidence of dengue.
5. What are the methods of preventing Dengue from occuring?
There are currently no approved vaccines for the dengue virus. Prevention thus depends on control of and protection from the bites of the mosquito that transmits it. The World Health Organization recommends a Integrated Vector Control program consisting of five elements:
(1) Advocacy, social mobilization and legislation to ensure that public health bodies and communities are strengthened,
(2) collaboration between the health and other sectors (public and private),
(3) an integrated approach to disease control to maximize use of resources,
(4) evidence-based decision making to ensure any interventions are targeted appropriately and
(5) capacity-building to ensure an adequate response to the local situation.
The primary method of controlling A. aegypti is by eliminating its habitats. This may be done by emptying containers of water or by adding insecticides or biological control agents to these areas. Reducing open collections of water through environmental modification is the preferred method of control, given the concerns of negative health effect from insecticides and greater logistical difficulties with control agents. People may prevent mosquito bites by wearing clothing that fully covers the skin and/or the application of insect repellent. By releasing mosquito larvae eating fishes into ponds and lakes, this disease can be controlled to ensure elimination of the mosquitoes.
Breeding places of Ae. Aegypti mosquitoes
6. Which areas in Ahmedabad are most prone to Dengue?
6. What measures are the Government and the Ahmedabad Municipal Corporation taking to control Dengue in the region.
The AMC along with the NVBDCP (National Vector Borne Disease Control Programme) in each region, conduct drives thrice a year to prevent the spread of dengue and malaria in the regions. Almost 15,00,000 dwellings are covered in such drives where special budget is allocated by the Government. Extra recruitment of field workers and health officers are done for such drives. The field workers are provided with handouts to spread information regarding malaria and dengue. They check the houses for any accumulation of water and mosquito density or if any individual is having fever and the symptoms.
The Government Hospitals also provide Dengue test for free for all localites and people who can give a permanent address proof in the Gujarat region.
Also free mosquito nets treated with insecticides were distributed among pregnant woman as they were at high risk state when it came do this disease
As Vijay Sir says, public health is a very sensitive issue. The idea is to mobilise people to come forward and help the Government to conduct smoother and more effective drives. Right now most of the population is unaware of the drives and the NVBDCP Board and the various measures being taken by the Government to curb the issue of Dengue.
There were more questions that I asked Vijay Sir pertaining to the existing design of the communication material which will be elaborated in the next post.
Daunting Dengue 